Advances in marketing of Japanese medical kit? (7)
I believe the answer is:
inroads
'advances' is the definition.
(to make inroads is to make progress or advances)
'in marketing of japanese medical kit?' is the wordplay.
'marketing of japanese medical kit?' becomes 'roads' (I can't explain this - if you can you should give a lot more credence to this answer).
'in'+'roads'='INROADS'
(Other definitions for inroads that I've seen before include "large quantities consumed when these are made" , "Making them is reductive" , "Ordains as offensives" , "Encroachments" , "Hostile attacks" .)